✔ 最佳答案
His best bet is to contact the licensing board in the jurisdiction where he wants to work. Different governing bodies have different rules about which licenses they do or do not recognize, and what it takes to get a license in one place when you have one from another - called "reciprocity" here in the United States. Some places recognize licenses from others and will license you with only a small fee, others will require additional testing, etc.
The contact information for licensing boards is readily available online, have him send an email.